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Joseph Wright  







Biodiversity; Canopy science  

NPR/NGS Radio Expeditions
20 Mar 1995

  • Panama
  • Panama City; Parque Natural Metropolitano; STRI Canopy Crane
  • 8.99223   -79.54582
  • Dry Forest
  • Stereo
    Sampling Rate
  • 48kHz
    Bit Depth
  • 16-bit
  • Sennheiser MKH 30
  • Sennheiser MKH 40
    Equipment Note
  • Stereo=1; Decoded MS stereo; Sennheiser MKH40 Cardioid Mid Mic and MKH30 Bidirectional Side Mic

"Life on the Brink"
Panama Crane #1
March 20, 1995

Interview with Joe Wright, research biologist with STRI and Kawow Iwagina (??? Kaoru Kitajima?), post-doc working with Wright
00:52 JW: Parque Natural Metropolitano, beside Panama City in the old canal area, land that reverted to Panama in 1979 and became a park in 1985. The forest here is a tropical dry forest, we get 1700 millimeters of rain a year, which is quite low by tropical force standards, and there is five month period during which it is very dry. In fact you can have no rain fall, as we did in 1992 during an El Nino event. Right now it's the late dry season, with perhaps a month to go. Its been dry for about four months at this point. The forest is partially deciduous the canopy is much more open than it will be in the wet season. Actually the time of greatest canopy closure, and greatest leaf area in the forest is December January. The first two months of the dry season. It's a problem -a paradox that we are working with. A question whether these plants are water limited or light limited. The dry season is time of much greater radiation b/c clouds absorb the wave lengths that are photosynthetically active. so we believe that the forest has adapted to put out a many ¬many of the plants are put out new leaves, and increase leaf area right at the beginning of the dry period to take advantage of the higher incoming radiation that's available when the cloud cover breaks up. 2:29
4:47-4:50 FX: crane moving up into the canopy
5:06 AC: we are in a small little cage with open sides. there is a little fence that comes up -not very high at all -and then there is a roof on it, and we are suspended by a cable that runs down to the roof i guess it's maybe 41/2 square -the floor?
JW: 1.2 meters by 1.2 meters -and we dignify it by calling it a gondola, not a cage. [laughter]
ac: So what do you see up here? why do you like being up here?
5:48 JW: well, this system, this crane system represents a real break-through in our ability to study the forest canopy. The traditional methods of getting access to the canopy are to climb ropes, and perhaps to build a platform in the canopy of a tree or to suspend a walk way between trees. But all of those methods depend on the tree to support the biologist weight. And any school child can tell you that trees don't put their leaves, their flowers, their fruits on the load bearing limbs, rather all of the organs of interest -except the wood itself -are out at the tips of small twigs and the smallest branches. They are up in the sun.

6:35 AC: Now when you say the items of interest what do you mean?
JW: Well the organ for carbon gain in plants is the leaf, and all of the reproductive organs, the entire reproductive biology of the plant is the flowers and the fruits. and those organs are all distal, they are at the tips of twigs and the smallest branches. there are a few plants that have their flowers, cauliferous [flowers which mature develop, etc. on the trunk of the tree] flowers, on the main trunk or on the main trunk, but the vast have their flowers at the tip of the growing maristem. so if you have gotten into your tree on a rope, or if you are sitting on a platform that is nailed into a tree, or attached to the tree you are sitting back on the load bearing limb and what you want to study you can't get to it. you are closer to it, but you can't reach it. and with this gondola system and with the tower crane -the tower crane is much taller than the forest. where you are raised up above the forest taken to where ever you want to drop into the forest, and then we descend, we are suspended from above, and we come dropping down from above so we can arrive right at the leaf or right at the flower. we can take physiological measurements on the leaf. we can study insects interacting with the plant as herbivores or pollinators or seed predators. we can make lots of observations that haven't been possible in the canopy before. and in a forest like this 90-95% of the leaves are in the canopy that's were the sun light is. the plants are designed to put their leaves up in the canopy, in the sun.
8:26 AC: I see leaves as we are going up here through the forest, and i don't think we are quite at the canopy height or are we at different canopies? I look down actually i see crowns and umbrellas of leaves beneath us as well.
8:40 JW: Well, these forests are layered. they have a structure. there's a ground layer of seedlings and herbaceous plants. then there is shrub layer that might be 2 meters tall. then there is a layer of treelets and perhaps saplings of big trees but there are many plants that as mature individuals are in the sub canopy, 10 to 15 meters tall in this forest. and then above that is the real canopy, which is in this forest 25-35 meters tall. nonetheless even though there are these many species of plants all of the herbs all of the shrubs and all of the treelets that as mature individuals are in the sub canopy, or the ground layer or the shrub layer nevertheless in this forest 90% of the leaves, more like 95% of the leaves are in that canopy layer. the canopy trees and the lianas and the epifites, but in this dry forest it is mostly the trees and the lianas really dominate the forest in terms of leaf biomass and leaf area.
9:45 AC: And lianna is a vine?

9:46 JW: Yes. It's a big woody vine.

10:30-11:58 birds, but lull of downtown traffic in bg, @ 11:03 an airplane 11:19 clear, strong birds

14:47 JW: we can reach 2 acres here of forest. the crane has a 51 meter boom and of course it goes around in a circle, all the way around, so if you go through the calculations that gives you 2 acres of forest canopy that we can reach with the crane. so yes, we go all the way around, in and out on the boom, up and down. here's the sun. this is the way the plants were designed to be seen up above from where the light is coming from. our view from the ground is something that is not relevant to the plants. they are oriented toward the incoming radiation.
15:40-15:44 -FX: clanging of crane extending out into the canopy
16:11 AC: look at this we are dropping right down on top of a tree (radio in bg)
16:26: AC: We are right on top of the trees
16:29 JW: that's the whole -beauty of the system. we are lowered from above and we can drop right on top of a tree right to the outer most leaves, and the upper most branches and the fruits and the flowers that we find here. the insect activity is incredibly heavy in this forest at this height. ;J
16:52 AC: we've just come next to a kind of some pipe structure that is stuck up here in the branches. what is that?
JW: this is an insect trap. it is an intersection trap it's a passive trap that captures insects as they fly by and by chance strike it. the apparatus on the bottom is a window pane with a funnel beneath it when the flying insect strikes the glass of the window pane some groups of insects characteristically drop and the funnel captures them, and they are funneled into a collection jar at the bottom. the structure -the little tent at the top is called a malaise trap. it is made out of just window mosquito wire when the flying insects hit that there are other groups of insects that fly up when they hit an obstruction and the little tent directs them toward another funnel, another collecting bottle. so we are collecting insects who just by chance strike the object and either drop down or flutter up.
17:53 AC: and what do you get from this? just an idea of what kind of insects are here up in the canopy?
17:57 JW: right we are motivated by some work done by Terry Erwin who is at the National Museum of the smithsonian in Wash. In the mid 1070s he came here to Panama and he broadcast insecticide into a canopy of one tree species I believe he did 20 different individuals and he put -before he broadcast the insecticide he put collecting sheets on the ground and when he fogged the trees with insecticide all of the dead insect bodies rained down on his collecting sheets. he then took that material home to Wash to see what he had, and he had astronomical numbers of species. totally, totally unexpected numbers of species, and the great majority of them were new to science. they had never been described before. and he, i believe something on the order of 12 hundred beetles species. just beetles in those collections. he estimated that perhaps 2 hundred of those species were specific to the tree -host specific to the tree species that he had fogged the insecticide into, and he did a few calculations based on the number of tree species int he tropics, and came up with an estimate of 30 million insect species in the canopies of tropical forests. in comparison, there is only 1.8 million species of all taxa of all kingdoms that have been described. so his hypothesis was that over 95% of the species on the planet were largely undescribed insects in the canopies of tropical forests. and one of the things that we are doing here is taking a closer look at that hypothesis since he only had insect bodies that had rained on to the ground he had no idea what the natural history of the organisms was -he made this estimate about host specificity, with the crane and the gondola system we are able to observe insects. we are able to sit here at a flower or at a new leaf and observe the herbivores, observe the pollinators, observe the behaviors of the seed predators who are able to move btwn about 100 species of trees and lianas that are underneath the crane another 20 species of epiphites; about 120 species of canopy plants to determine if the species are indeed host specific.
20:30 AC: what is an epiphite?
20:32 JW: an epiphite is an herbaceous plants and they have no connection to the soil. they are rooted on the other branches of trees. the roots don't really serve the function that you think offer roots, rather they are to hold on. they don't tap the xylem or phloem -the vascular system of the host plant at all, the roots just grasp the host plants. Orchids, bromeliads are well known epiphjtes and there's many, many other plant families with epiphites here in the tropics.
21:10 AC: Just looking around here at the tips of these branches, there are leaves that are all chewed up and full of holes. i gather that's what's happened here. is that what you see here?
21:23 JW: yup. and in fact we have bee able to establish which insect has been doing each of these types of damage to these leaves. that's one of the ways we are doing this study. we find a scar on seed or a hole on a leaf and each one of these holes is characteristically distinct and then we just look and find the insect that is making that type of scar on the plant tissue. for example here's the little brown scrapings on the upper surface of the leaf are made by a weevil about 2 millimeters long. these little scalloped parts of leaf tissue along the margin that have been removed it turns out they have been made by exactly the same weevil. the adult weevil will scrape these little holes in the leaf, that's probably the feeding behavior. and then occasionally it will walk over to the edge of the leaf and begin to cut. and will cut out a little -what is that a dime size? scalloped piece from the margin, and the piece just falls to the forest floor and we believe that what the weevil is doing is that it is a female who is doing that cutting and she is depositing an egg on that little piece of leaf before it drops to the forest floor and then the larval weevil is developing in the leaf litter down in the ground. so each one of those scars i could tell you which insect. i couldn't tell you the species because most of the species are undescribed, but i could show you the insect and tell you the genus of the insect making the damage.22:58 what we are finding with these traps is that we are getting the thousands of species that Terry Erwin found here and incidentally Terry Erwin worked on this very same species tree. it's the most common tree under the canopy crane, and just by coincidence it's the species that terry erwin fogged. we are finding the thousand of species that he would have predicted would be here with the interception traps. but when we look at the plant look at the flowers, look at the seeds, look at the bark we are not. we are finding perhaps a dozen species of beetle. the other, the remaining thousand that we are finding are apparently tourists. they are beetles in transit btw that tree over there and t he epiphyte over here..............and another tree we found in 2 visits to it of about 15 mins each we found 45 different beetle species in the flowers of this tree that i will show you now. so some of these trees do have astronomical numbers of species. other have much much more limited insect faunas. but the insects are moving around so the question of host specificity and the question of what the insect is doing behaviorally, what's the ecology of the insect, is going to be very critical to any estimate of the global number of insects in these forests.
24:41 AC: what species of tree is this?
24:44 JW: It's luias simania in the family tiliaciae.
AC: and does it have a popular name? that people would know?
JW: no one in the united states would know the popular name. it is guasi guasimo here in panama......but the common names
changes .......
25:42 AC: so how many people actually plunge over the edge of this thing and are scraped from the ¬
JW: no one so far. we may loose a grad student one of these days. people get rather cavalier after they've worked up here
for a couple of months and they begin to forget exactly how high
they are and start to do things like climbing out up on the roof because they want to get something -a picture...
AC: how high are we?
26:16 JW: we are about less than 20 meters, but close to 20 meters right now. 18 meters. not bad. the tallest trees are about 35 meters here -35-36.
26:34 AC: does it bother you any more to be up in this thing? JW: no it never did. i used to paint houses in college......
27:58 JW: now we are up about 30 meters.
AC: ohhhhhhhhhhhhhhhhh....
JW: alex do you want to go down?
AC: he's going to let us back down. isn't he?
JW: yeah. oh boy. i know this is an uncomfortable feeling..... .
28:41 AC: [awful groaning sound]
28:45 JW: I don't know if this is a story that you will want to tell your audience, but this is an economically important tree here in Central America. the ecology is very similar to's a hard wood, it's an early successional plant that grows very rapidly but has a very, very beautiful hard wood. and the USAID was interested in it, so they funded a project to grow it in plantation situations to see if that was feasible. and the project was a complete failure. they didn't get any germination of their seedlings. so they brought in robin foster to ask what had happened why did it go wrong, after the fact. after all of the money was spent. and it turned out that they had used sterile seeds. what they had used was dried flowers, and what happens is it is in the family baragonaciae (???) the flower has got 5 petals, and after it has pollinated the seed develops and the corolla [AC notes: you are reaching out from the gondola to grab a little petal] flower -the base of the corolla swells slightly -this is a fertile seed after pollination -and that's it. then pollination the flower dries out and the petals of the flower become the wings of a wing dispersed seed. so if i drop this it will helicopter away and if there is wind blowing it will go a great distance. and what the AID people had done was gone to the plants where there's huge numbers of these dried flowers and gathered them off the plant. but they were not pollinated they were sterile material that they spent well over a million dollars trying to germinate in a massive nursery operation. 30:47 This is an unremarkable tree. It is a very simple flower. we have an entomologist that is here from Norway who has come to visit these flowers twice now. Each stop was for about an hour; and he has found 45 different species of beetles ¬micro-beetles -less than 2 millimeters long in these flowers. 17 different weevil species and the remainder of from a variety of families w/in the beetles. the only thing you can see obviously are the bees, here's a hamicterin -that is an insect that sucks plant tissue, it's mouth parts are like a long stylus that's inserted into the phloem and it sucks the sap of the plant -[ac: you can't really see that guy] see that little green guy [ac: oh yeah] 31:54 there's a lot of ants. it's an ant plant. [ac: oh yeah you can see the little ants crawling around]you can see the branching pattern back -where there is the branching there is a swollen spot -that's hollow, and the ants will live in there. there will be an ant nest. and the ants patrol the whole plant and they remove caterpillars and other herbivores from the plant. but apparently there's just a vast number of beetles in these flowers.
32:35 AC: [notes to himself]this is a kind of clump of white flowers. it looks kind of like a pin cushion.......1-2-3-4-5¬little five petal flowers, white flowers w/a little kind of rosy base....
33:05 JW: the beetles are down in the corolla. there's the ovule. looks like it's beginning to swell. this one has been pollinated. but apparently, you just keep opening flowers you keep finding flowers, and you keep finding beetles, and you keep finding new species.
33:26 AC: did you study these trees before the crane -before you had this crane? did you get up here and do this kind of stuff?
JW: it was impossible to do this sort of stuff. these flowers are out on the finest twigs on this tree and to get to them w/traditional climbing techniques with ropes or w/walkways suspended btwn trees was just impossible we are at the top of the canopy and we are looking at flowers that are on the finest, lightest twigs that would not support your weight. you would have to come at them from above. botanists would have been able to study this mat'l by looking for fallen trees or by using a shotgun to shoot the flowers down, or by using a pole-cutter to cut a low branch or by climbing the tree and using a pole-cutter from half way up. but an entomologist to be able to look at the behaviors of the insects that are visiting the flowers and to be able to open active flowers and look for the insects involved in pollination down in the flower, that has not been possible before for these canopy plants. the other thing to remember is that we have a hundred species of trees here. in the park which in only 600 acres we have about 500 species of trees, about a hundred of which are underneath the crane. the diversity is much, much, much higher than what you are used to from the temperate zone. so, for all of those hundred species, no, no one has been able to do this before. 35:08
35:09-35:34 OK ambi -birds, w/bg of city cars moving (?)
35:35 JW: now that's fertile. that's swollen through the ovule here's the large green thing. see how much larger it is? that's the seed. wondering if there are beetles in here too. but i think that most of the beetles have been in the flowers and not in the seeds. so you can see how AID went wrong. that's fertile...........
36:42 JW: how are you feeling? not too good?
AC: uhhhhh..... i prefer ground to 30 meters ...but, it is very interesting.
36:52 JW: there's another interesting flower over here we can go take a look at...
36:56 AC: ahhhh¿..ehhhhh.....
JW: do you want to go down?
37:01 CAROLYN: maybe we can just talk about biodiversity. what are we really seeing? and what is the canopy?
AC: well, why don't you just -i don't quite understand what you mean -so go ahead...
37:20: CAROLYN: well we are up quite high in the sky and we are actually able to see biodiversity in all of its richness. can you explain your interpretation of biodiversity, and what we are seeing.
37:42 JW: well, i would hazard -i would guess that we are in the heart of biodiversity here. first there is a gradient and species richness in biodiversity latitudinally. there's many more species in the tropics than there are in what looks like similar vegetation in the temperate zone. the richest forests in the temperate zone are the Cove Forests of the Smokey Mtns which might have 60 species of tree. here in this park there's 500 species of tree and this is a depauperate tropical forest. there's a low rain fall, dry tropical forest. if we went to the wet Caribbean slope where there is twice as much rainfall we would have a thousand species of tree in the same area. then w/in this very rich tropical forest there is another [good bg of birds chirping] gradient, from the ground to the canopy. the ground is in deep shade. in these forests about 1% of solar radiation manages to penetrate through to the ground. and that solar radiation is energy for plant life. the productivity of the plants is going to limit all else because those are the autotrophs and all of animals depend on the plants. as you get higher in the forest more and more light manages to penetrate. and here we are above the forest in full sunlight. and here productivity is at its maximum. as i've said before 95% of the leaves in this forest are in the canopy. and 95% or more of the carbon that is being fixed by photosynthesis is being fixed here in the canopy. and just for that reason the animals would be expected to be here. and in fact what you can see with this flowering tree behind us, and the increased levels of insects activity, that is in fact the case. And the species richness in particular of the insects of the arthropods, spiders, mites and insects in these canopies is astronomical. it is unexplored. if you were to collect these 45 species of beetle that we found in these flowers of this tree perhaps 80% of them would be undescribed, new to science. and here in central panama the Smithsonian tropical research institution has been located a stone's throw away for the past 50 years. It's one of the best studied pieces of tropical forest that there is, and yet 80% of the beetle species are undescribed in this forest 40:42
CAROLYN: and why does it matter?
49:50 JW: that's a perennial question. ~here are dozens of reasons it matters. but the most compelling reason, i think, is that we don't know the role of these insects we don't know what services they are providing this forest. if you were to lose the insects or if you were to lose plant species how would the remainder of the forest respond? can you have a tropical forest-, w/half of the species in it? it would be a very different place, but would it serve the same role in global carbon cycle, or would we see tremendous changes. and these forests cover a sixth of the planet's surface. so as we disrupt them we are going to see potentially very great changes in global carbon cycle, for example. .......i don't think alex is going to ask me anything, except -let's go down!
42:09 CAROLYN: just one last thing. for someone sitting in a temperate zone listening to this how would you describe how important it is to them that this biodiversity be maintained.
42:24 JW: in the near term if you were to - the implications for disrupting the global carbon cycle in the near term aren't going to be too severe. in the next 50 years but in the longer term consequences are potentially very severe. if we disrupt the global carbon cycle to the point where we get global warming and changes in atmospheric C02 and the greenhouse gases. all the climate models predict that the mid-western us which is now the bread basket of the world is going to become desert under the 5 degrees C warming. and we have already seen 1 degree C warming in the last decade. so i think those people are going to have a real impact. and right now the burning of tropical forests is contributing about 16% of the excess carbon dioxide into the atmosphere. the burning of fossil fuels is about 80% and the conversion of tropical forest to pasture and swidden (?) agricultural is about 16% of the disruption of global carbon cycle.
43:42 AC: when you say excess what do you mean excess carbon cycle?
JW: a forest -a mature forest is at equilibrium. the living plants are fixing carbon through photosynthesis, but there is also dead plant material that is decomposing, releasing carbon. a mature forest is very close to equilibrium. but when you take a big forest that is 35 meters tall w/hundreds of tons of wood per acre, cut it down and burn it, you are suddenly releasing all of that carbon. and if you then replace the forest with a pasture that's grazed by cattle that's happening throughout central America and South America you are having a much, much lower biomass of carbon -of plant tissue -so you are releasing a huge amount into the atmosphere. and the burning of fossil fuels is very similar. these fossil fuels have been locked up since the carboniferous in deposits and we are extracting them and burning them and releasing that carbon into the atmosphere .......................
45:06 JW: my name is Joe Wright. I am a research biologist working with the Smithsonian Tropical Research Institute here in Panama.
AC: and where are we right now?
JW: we are in the Metropolitan Park adjacent to Panama City, Panama along the Pacific coast of the Pacific mouth of the Panama canal ....we are about 30 meters above the ground, and just among the tops of the tallest trees in this tropical dry forest ......45:50 we are riding in the gondola raised into the tops of the trees in a tropical dry forest by a construction tower crane. we are adjacent to panama city in the pacific mouth of the panama canal.....46:18 we are riding in a gondola 30 meters above the ground......48:22 we are in the tops of the trees in a tropical dry forest riding in a gondola raised to these heights by a construction tower crane. the forest is in central panama, adjacent to panama city in the pacific mouth of panama canal............... .
52:10-52:22 good ambi: the gondola landing on ground -clanging of crane and gondola
52:23 AC: so how long would you normally stay up doing something on that and how often is the crane used?
52:30 JW: the crane is used 7 days a week. dawn to dusk, typically. in particular plant physiologists make measurements that have to be made repeatedly during the day and will go from before dawn until dusk. the entomologists tend to be less demanding of the crane. they make observations -behavioral observations. we are doing a lot of work at night now with entomologists. many of the insects seem to be much more active at night. the birds and many of the insectivorous animals are oriented visually and at night the predation levels must be a lot lower. there's a lot of insect activity at night. so its 7 days a week. we have two operators to keep on that schedule.
through end: ambi inside the gondola -ok, but can hear people talking in bg.
using MS pair sennheisers -recording using Q 30 D7 reporters kit...............
58:23-END ambi: "roaring of automobile, with a little bit of jungle sound" ....using MS pair -airplane in bg, ok

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